Vane-type fluid motor



- Sept. 30, 1969 J. a. LUTZ ET AL VANE-TYPE FLUID MOTOR Filed Nov. 6. 1967 INVENTORS JOHN G. LUTZ EMANUEL 6. SPYR/DAKIS ATTORNEY United States Patent 3,469,500 VANE-TYPE FLUID MOTOR John G. Lutz, London, England, and Emanuel G. Spyridakis, Belle Mead, N..I., assignors to Ingersoll-Rand Company, New York, N.Y., a corporation of New Jersey Filed Nov. 6, 1967, Ser. No. 680,859 Int. Cl. Ftllc 1/00; F04c N00 US. Cl. 91-121 6 Claims ABSTRACT OF THE DISCLOSURE A vane-type fluid motor provided with normally closed passages which, upon predetermined vane wear, cause suflicient pressurized fluid to pass at least one of the vanes whereby the speed of the rotation of the rotor, and hence the power of the motor, is substantially reduced to denote such vane wear. In one embodiment, the passages are formed in the rotor in communication with the vane slots and are normally closed by the vanes. In another embodiment, the passages are formed through the vanes and normally closed by the rotor.

BACKGROUND OF THE INVENTION The present invention relates to fluid powered motors and more particularly to vane-type fluid motors such as, by way of example, those employed in pneumatic hand tools.

During the operation of a vane-type fluid motor, the vanes of the motor are continuously in engagement with the walls of the chamber containing the rotor. This engagement, of course, causes wear of the vanes which, if continued, reduces the width of the latter sufficiently that they eventually tip in their slots and jam the motor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a new and improved vane-type fluid motor which is particularly constructed and arranged to denote a predetermined vane wear less than the suflicient to cause jamming of the motor.

Another object of the invention is to provide a new and improved vane-type fluid motor which is particularly constructed and arranged to be substantially reduced in power upon such predetermined vane wear whereby this power reduction serves to denote the vane wear.

These objects, and those other objects and advantages of the invention which will be apparent from the following description taken in connection with the accompanying drawings, are attained by the provision of a motor comprising a casing containing a wall peripherally defining a cavity closed at its opposing ends, and a rotor rotatably disposed in the cavity cooperating with this wall to bound a working chamber and including laterally extending slot means. An inlet passage means communicates with the working chamber for supplying pressurized fluid thereto; and an exhaust passage means communicates with the working chamber for discharging exhaust fluid therefrom. Vane means are slidably mounted in the slot means in engagement with the aforementioned wall to divide the working chamber into a plurality of variable volume pockets; and a normal- 3,469,500 Patented Sept. 30, 1969 "ice BRIEF DESCRIPTION OF THE DRAWINGS Referring to the drawings:

FIG. 1 is an elevational, sectional view of a vane-type fluid motor constructed in accordance with one embodiment of the present invention;

FIG. 2 is an elevational sectional view taken on line 2-2 of FIG. 1, looking in the direction of the arrows;

FIG. 3 is an elevational, sectional view generally similar to FIG. 2, but showing the motor after the aforementioned predetermined vane wear;

FIG. 4 is an elevational, sectional view, generally similar to FIG. 2, of a vane-type fluid motor constructed in accordance with an alternative embodiment of the invention; and

FIG. 5 is a perspective view of one of the vanes of the motor shown in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout the several views. FIGS. 1 through 3 illustrate a vane-type pneumatic motor designated generally as 10 which comprises a housing or casing -12 containing an annular wall 14 peripherally defining a rotor cavity 16. The opposing ends of the rotor cavity 16 are closed by end walls 18, 20 which include aligned openings 22, 24 and carry bearings 26, 28, respectively. A cylindrical rotor 30 is eccentrically positioned in the rotor cavity 16 with its opposing ends rotatably engaging the end walls 18, 20 and cooperates with the wall 14 to peripherally define a generally crescent-shaped working chamber 32 extending the length of the rotor cavity 16. The rotor 30 is rotatably mounted by stub shafts 34, 36 which project through the openings 22, 24 and are supported by the bearings 26, 28, respectively. The stub shaft 36, as will be understood, is suitably connected in a conventional manner to the apparatus (not shown) driven by the motor 10 whereby rotation of the rotor 30 drives such apparatus.

The casing 12 contains a threaded inlet bore 38 which is-adapted for connection to a conventional pneumatic conveying hose (not shown) communicating with a source (not shown) of pressurized air. The inlet bore 38, as illustrated in FIGS. 2 and 3, communicates through a bore 40 and an elongated inlet chamber 42 with one end of the Working chamber 32 to supply pressurized air to such end of the working chamber 32 throughout a substantial portion of the length of the rotor cavity 16. The casing 12 also contains a pair of threaded exhaust bores 44, 46 which are adapted to be connected to pneumatic conveying hoses (not shown) arranged to discharge exhaust air at a location remote from the motor 10. The exhaust bore 44 is connected by a bore 48 and an elongated chamber 50 to the end of the working chamber 32 opposite to that communicating with the inlet bore 38; and the exhaust bore 46 is connected to the working chamber 32 intermediate the ends of the latter by an elongated chamber 52 and a plurality of exhaust ports 54.

The rotor 30 is provided with a plurality of generally radial, vane mounting slots 56 which each longitudinally extend the length of the rotor 30. The slots 56 each slidably contain a vane 58 which rotatably engages the end walls 18, 20 along its opposing ends and the wall 14 along its length. The vanes 58 divide the working chamber 32 into a plurality of pockets 60 (each bounded by the wall 14, the rotor 30, and two adjacent ones of the vanes 58) which vary in volume during the rotation of the rotor 30.

The present invention comprises the provision of passage means, normally closed during the operation of the motor 10, which are operable in response to predetermined vane wear to pass suflicient air by at least one of the vanes 58, whereby adjacent pockets 60 are communicated to cause the speed of the rotation of the rotor 30 (and resultantly the power of the motor to be substantially reduced. More particularly, as illustrated in FIGS. 1 through 3, this passage means includes a first pluarlity of bores or passages 62 formed in the rotor 30 communicating each of the slots 56 with the pocket 60 immediately adjacent one side of their respective contained vanes 58, and a second plurality of bores or passages 64 formed in the rotor 30 communicating each of the slots 56 with the pocket 60 immediately adjacent the opposing side of their respective contained vanes 58. The passages 62, 64, as illustrated in FIG. 1, are arranged at intervals throughout the length of the rotor 30 and communicate with their respective connected slot 56 at intervals throughout its length. The passengers 62, 64 moreover, as will be noted from FIGS. 2 and 3, communicate with the slots 56 through opposing walls of the latter and, although normally blocked from intercommunication by the vanes 58, are particularly arranged to communicate through the slots 56 after the width of the vanes 58 has worn a predetermined amount but before the vanes 58 wear sufliciently to tip in the slots 56 such as might jam the motor In the operation of the motor 10, as illustrated in FIG. 2, the passages 64 are normally closed from communication with the passages 62 by the vanes 58. Thus, the rotor 30 is normally rotatably driven in the conventional manner by pressurized air entering the motor chamber 32 through the inlet bore 38 and exhausting therefrom through the bores 44, 46. The frictional engagement between the vanes 56 and the wall 14 accompanying this normal operation causes the width of the vanes 58 to progressively wear whereby their width is eventually reduced a predetermined amount to a predetermined lesser width. Upon this predetermined wear of the vanes 58, as illustrated in FIG. 3, they become sufliciently narrow whereby at least one of the vanes 58 uncovers the passages 62, 64 communicating with its slot 56. Thus, adjacent pockets 60 are communicated through the passages 62, 64 and such slot 56, and resultantly the speed of the rotation of the rotor 10 is substantially reduced (and, if the passages 62, 64 be large and numerous enough, stopped) before the vane wear becomes sufficiently great to cause jamming of the motor 10.

FIGS. 4 through 5, wherein parts similar to those shown in FIGS. l-3 are designated by the reference character for their similar previously described parts followed by the suflix a illustrates a vane-type pneumatic motor 10a embodying an alternative embodiment of the invention. The motor 10a differs from the beforedescribed motor 10 only in that the passages 62, 64 of the latter have been replaced by a plurality of bores 66 formed at intervals transversely through each of the vanes 58a. The bores 66, as will be understood, are suflicient in number and size to cause their communication of adjacent pockets 60a to substantially reduce the speed of, and preferably stop, the rotation of the rotor 30a, and are particularly located whereby they are normally closed by the walls of the slots 56a; but communicate adjacent pockets 60a prior to the width of the vanes 58a being reduced to a degree possibly causing jamming of the motor 10a.

The operation of the motor 10a is identical to that of the motor 10, except that upon the predetermined wear of the width of the vanes 56a the bores 66 communicate adjacent pockets 60a, and hence is believed to be apparent from the aforegoing description of the operation of the motor 10.

From the aforegoing it will be seen that we have provided new and improved means for accomplishing all of the objects and advantages of our invention.

What is claimed is:

1. A fluid operated motor comprising a casing containing a wall peripherally defining a cavity closed at its opposing ends, a rotor rotatably in said cavity cooperating with said wall to bound a working chamber and including a plurality of vane mounting slots extending inwardly from its periphery, inlet means for supplying pressurized fluid to said working chamber, discharge means for discharging exhaust fluid from said working chamber, a vane slidably mounted in each of said vane mounting slots, said vanes each having an inner end in their respective slot and an outer end in slidable engagement with said wall whereby said vanes divide said working chamber into a plurality of pockets variable in volume during rotation of said rotor, and passage means for passing fluid from said working chamber by at least a single vane, said passage means comprising a plurality of passages located in one of said rotor and single vane to be normally closed by the other thereof throughout the rotation of said rotor and to be opened to fluid flow therethrough when the outer end of said single vane wears an amount suflicient that said inner and thereof, although still retained in its respective slot sufliciently to prevent said single vane from tipping such as might jam the motor, is at a predetermined location adjacent the periphery of said rotor, and said passages being of a combined flow volume sufficient that the speed of rotation of said rotor is substantially reduced upon fluid flow therethrough.

2. A fluid operated motor according to claim 1, wherein said passages are constructed through the thickness of said single vane intermediate the inner and outer ends thereof.

3. A fluid operated motor according to claim 1, wherein said passages are constructed in said rotor to communicate the slot containing said single vane with the pockets adjacent opposing sides of said single vane.

4. A fluid operated motor comprising a casing containing a wall peripherally defining a cavity closed at its opposing ends, a rotor rotably in said cavity cooperating with said wall to bound a working chamber and including a plurality of vane mounting slots extending inwardly from its periphery, inlet means for supplying pressurized fluid to said working chamber, discharge means for discharging exhaust fluid from said working chamber, a vane slidably mounted in each of said vane mounting slots, said vanes each having an inner end in their respective one of said slots and an outer end slidably engaging said wall whereby said vanes divide said working chamber into a plurality of pockets variable in volume during rotation of said rotor, passage means for passing fluid from said working chamber by each of said vanes, said passage means including for each vane a plurality of passages in one of said rotor and such vane, said passages being located in said one to be normally closed by the other of said rotor and vane throughout the rotation of said rotor and to be opened to fluid flow therethrough when said outer end of such vane wears an amount suflicient that during at least a portion of the rotation of the rotor said inner end of such vane, although still retained in said slot sufliciently to prevent such vane from tipping such as might jam the motor, is at a predetermined location adjacent the periphery of said rotor, and said passages 5 6 being of a flow volume that the speed of rotation of said 2,962,257 11/1960 Allingham 253S9 rotor is substantially reduced upon fluid flow therethrough. 3,014,431 12/ 1961 Bussche 91-l35 X 5. A fluid operated motor according to claim 4, 3,102,493 9/1963 Davin 91--135 X wherein said passages comprise bores formed through the thicknesses of said vanes intermediate the inner and outer 5 FOREIGN PATENTS ends thereof.

6. A fluid operated motor according to claim 4, 451,416 10/1927 xwherein said passages comprise bores formed in said rotor 221712 1911 Great i i for communicating each of said slots with the pockets 398,141 9/1933 Great Bmamadjacent opposing sides of their respective contained vane. 10 EVERETT A POWELL JR Primary Examiner References Cited UNITED STATES PATENTS 103 136 706,158 8/1902 Charles 91135 15 2,371,081 3/1945 Tucker et al.

US. Cl. X.R. 

